Language.Haskell.Pretty

haskell-src-1.0.2.0: Support for manipulating Haskell source code

Copyright | (c) The GHC Team, Noel Winstanley 1997-2000
License | BSD-style (see the file libraries/base/LICENSE)
Maintainer | libraries@haskell.org
Stability | experimental
Portability | portable
Safe Haskell | None
Language | Haskell98

Language.Haskell.Pretty

Contents

- Pretty printing
- Pretty-printing styles (from Text.PrettyPrint.HughesPJ)
- Haskell formatting modes

Description

Pretty printer for Haskell.

Synopsis

- class Pretty a
- prettyPrintStyleMode :: Pretty a => Style -> PPHsMode -> a -> String
- prettyPrintWithMode :: Pretty a => PPHsMode -> a -> String
- prettyPrint :: Pretty a => a -> String
- data Style :: * = Style {
  - mode :: Mode
  - lineLength :: Int
  - ribbonsPerLine :: Float
  }
- style :: Style
- data Mode :: *
  - = PageMode
  - | ZigZagMode
  - | LeftMode
  - | OneLineMode
- data PPHsMode = PPHsMode {
  - classIndent :: Indent
  - doIndent :: Indent
  - caseIndent :: Indent
  - letIndent :: Indent
  - whereIndent :: Indent
  - onsideIndent :: Indent
  - spacing :: Bool
  - layout :: PPLayout
  - linePragmas :: Bool
  - comments :: Bool
  }
- type Indent = Int
- data PPLayout
  - = PPOffsideRule
  - | PPSemiColon
  - | PPInLine
  - | PPNoLayout
- defaultMode :: PPHsMode

# Pretty printing

class Pretty a

Things that can be pretty-printed, including all the syntactic objects in Language.Haskell.Syntax.

Instances

Pretty HsGuardedAlt |
Pretty HsGuardedAlts |
Pretty HsAlt |
Pretty HsFieldUpdate |
Pretty HsStmt |
Pretty HsPatField |
Pretty HsPat |
Pretty HsExp |
Pretty HsLiteral |
Pretty HsType |
Pretty HsQualType |
Pretty HsSafety |
Pretty HsGuardedRhs |
Pretty HsRhs |
Pretty HsBangType |
Pretty HsConDecl |
Pretty HsMatch |
Pretty HsDecl |
Pretty HsAssoc |
Pretty HsImportSpec |
Pretty HsImportDecl |
Pretty HsExportSpec |
Pretty HsModule |
Pretty HsCName |
Pretty HsOp |
Pretty HsQOp |
Pretty HsName |
Pretty HsQName |
Pretty Module |

prettyPrintStyleMode :: Pretty a => Style -> PPHsMode -> a -> String

pretty-print with a given style and mode.

prettyPrintWithMode :: Pretty a => PPHsMode -> a -> String

pretty-print with the default style and a given mode.

prettyPrint :: Pretty a => a -> String

pretty-print with the default style and `defaultMode`.

# Pretty-printing styles (from Text.PrettyPrint.HughesPJ)

data Style :: *

A rendering style.

Constructors

Style |
Fields mode :: Mode The rendering mode lineLength :: Int Length of line, in chars ribbonsPerLine :: Float Ratio of line length to ribbon length

Instances

Eq Style |
Show Style |
Generic Style |
type Rep Style = D1 D1Style (C1 C1_0Style ((:*:) (S1 S1_0_0Style (Rec0 Mode)) ((:*:) (S1 S1_0_1Style (Rec0 Int)) (S1 S1_0_2Style (Rec0 Float))))) |

style :: Style

The default style (`mode=PageMode, lineLength=100, ribbonsPerLine=1.5`).

data Mode :: *

Rendering mode.

Constructors

PageMode | Normal
ZigZagMode | With zig-zag cuts
LeftMode | No indentation, infinitely long lines
OneLineMode | All on one line

Instances

Eq Mode |
Show Mode |
Generic Mode |
type Rep Mode = D1 D1Mode ((:+:) ((:+:) (C1 C1_0Mode U1) (C1 C1_1Mode U1)) ((:+:) (C1 C1_2Mode U1) (C1 C1_3Mode U1))) |

# Haskell formatting modes

data PPHsMode

Pretty-printing parameters.

Note: the `onsideIndent` must be positive and less than all other indents.

Constructors

PPHsMode |
Fields classIndent :: Indent indentation of a class or instance doIndent :: Indent indentation of a `do`-expression caseIndent :: Indent indentation of the body of a `case` expression letIndent :: Indent indentation of the declarations in a `let` expression whereIndent :: Indent indentation of the declarations in a `where` clause onsideIndent :: Indent indentation added for continuation lines that would otherwise be offside spacing :: Bool blank lines between statements? layout :: PPLayout Pretty-printing style to use linePragmas :: Bool add GHC-style `LINE` pragmas to output? comments :: Bool not implemented yet

type Indent = Int

data PPLayout

Varieties of layout we can use.

Constructors

PPOffsideRule | classical layout
PPSemiColon | classical layout made explicit
PPInLine | inline decls, with newlines between them
PPNoLayout | everything on a single line

Instances

Eq PPLayout |

defaultMode :: PPHsMode

The default mode: pretty-print using the offside rule and sensible defaults.